Strain-insulator.



B. A. PLIMPTONI STRAIN INSULATOR.

APPLICAHON FILED JAN.25. I917.

1 ,266,7 1 1 Patented May 21, 1918.

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his ATTORNEYS B. A- PLIMPTON.

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. AFPLIC .25.1917. v 1 ,266,71 1. Patented May 21,1918.

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I I I? I UNITED STATES,

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STRAIN-INSULATOR.

Specification of Letters latent.

Patented May 21, 1948.

Application filed January 25, 1917. Serial in. 144,347.

To all whom it may concern:

Be it known that T, BENTLEY A. PLIMP- TON, of Victor, in the county ofOntario and State of New York, have invented certain new and usefulImprovements in Strainl nsula-tors; and I do hereby declare thefollowing to'be a full, clear, and exact description of the same,reference being had to the accompanying drawin s, forming a part of thisspecification, an to the reference characters marked thereon.

The invention has for its object to improve the structure of straininsulators, more particularly with a view to affording a cementlessconnection between a metal cap, stud or connecting member, and theinsulating portion or member of the usual type of strain insulatingunit. A-further object of the invention is to afford a connection thatwill be sufliciently strong to withstand any of the strains to whichsuch an insulator is usually subjected, also to entirely eliminate theuse of cement in joining a cap, stud or connecting member, and theinsulating portion, and further to pro vide an economical constructionthat can be v readily made'and assembled without eXces sive cost. Tothese and other ends the invention consists in certain improvements andcombinations of parts, all as will be hereinafter more fully pointed outin the claims at the end of the specification.

In the drawings:

Figure 1 is a side elevation of an insulator constructed in accordancewith my invention;

Fig. 2 is an enlarged sideview showing the metal cap in section, aboutto be assembled on the'insulating unit;

Fi 3.is a sectional view showing the position of the parts after the capis locked Fig. 4 is a horizontal sectional view on the line t e or Fig.3;

Fig. 5 is a vertical sectional view taken centrally of the'insulator,and

Fig. 6 is a horizontal sectional view on the line 6 of Fig. 5.

' Similar reference characters throughout the several'views indicate thesame parts.

According to the'construction herein disclosed, which'illustrates apossible embodiment for carrying out my invention, there is shown ausual type of straininsulator embodying a metal cap 1 and an insulatingportion or member which includes the flaring portion or skirt 2 and thehead or top portion 3. The top portion?! has formed thereon what I havetermed a thread, indicated by 4 and extending partially around .theinsulating unit and terminating at its The cap 1 is provided at itslower portion with an inturned flange 6 and carries a locking memberhaving one end in fiXed relation and the other end in movable relationtherewith to permit separation of the ends, and threading the lockingmember on the insulating portion. Vith this in view I preferably employa split ring designated by 7. One end of the said ring has an outwardlyextending projection or lug 8 which engages an opening or recess 9 inthe cap, while the other end of the ring is movable so as to permit theparts to assume the rela tive position shown in Fig. 2, where the freeend of the locking member is engaging the upper side of the thread 4 andthe fixed end lies between the opposite ends of the thread 4 and isaboutto pass under the shoulder 5. This is the first position that isassumed when the cap is assembled upon the insulating portion and byturning the cap to the right from the position shown in Fig. 2, thelocking member is carried with it until itis entirely under the thread 4and locked in place by the shoulder 5. After this relative positioningof the parts is accomplished it is practically impossible to remove thecap from the insulating portion except by breaking one'of the parts.When the locking member is in locked relation, it rests upon the flange6 and is located between it and the lower edge of the thread 4, as shownclearly in Fig. 3.

In the usual operation of devices of this character, it is common toemploy several insulators which are interconnected and support aconductor, for which purpose the cap 1 carries a lug or extension 10having an opening 11 that receives a pin 12 cooperating with aconnecting member 13 on the adjacent insulator unit. Each insulatingportion is formed hollow to receive a stud 'or connecting member 13, thesame being also hollow as shown in Fig. 5, and provided with theopenings 14 in whichthe pin 12 is located. It is necessary to retain theconnecting member or sleeve 13 within the hollow portion of theinsulating portion and to this end the latter is provided with ashoulder 15 which receives a plurality of locking devices and therebyprevents the connecting member 13 from being withdrawn. The

connecting member or sleeve 13 is provided 'with a series of openings 16within which are, located the locking devices 17 These latter are in theform of blocks which are freely movable in the openings and are providedwith'inclined or beveled surfaces 18 to engage the shoulder 15aforesaid. The locking devices 17 are prevented from withdrawal awayfrom the locking shoulder by means of a sleeve or thimble 19 locatedwithin the connecting member and held in place by any suitable retainingmeans. In assembling the parts just described, the connecting member isfirst inserted within the hollow portion of the insulator, and thelockingdevices 17 are then inserted in the ment with said shoulder I 20therewithin,

I portion having a thread 1 in a locking shoulder,

connecting member and forced through the openings 16 by' any. suitableinstrument or tool for the purpose, un'til theyengage the shoulder 15.The thimble or sleeve 19is then dropped or positionedwithin theconnecting member with its outer surface engaging the inner ends of thelocking devices 17. The thimble 19 is held in lace'preferably byinserting a cement filling material as shown in Fig. 5.

I claim as my invention: 1. The combination with an insulating portionhaving a thread thereon terminating of a cap cooperating insulating andcarrywithdrawal from the locking la tter.

of a cap at ing a'locking member having one end in fixed relation andthe other end in movable relation with the cap to permit the lockingmember to be threaded upon theinsulating portion and to lockingly engageunder said thread. I

4. The combination with an insulating portion having a thread thereonterminating in a shoulder, of a cap secured upon the insulating portionand carrying a locking member in the form of a split ring having one endin fixed relation and its opposite end in movable relation with the capto permit threading the locking member upon the insulating portion andbringing it into locked relation with said shoulder.

5. The combination with an insulating portion having a locking shoulderextending partially therearound, of a cap secured upon nheinsulatingportion and carrying a lock- 111g member in the form of a split ring,one end of which engagesa recess in the cap while the opposite end isfreelymovable to upon the insulating portion by initially placing thefree end of the locking member beneath said shoulder'andturning the capuntil the entire'locking member is disposed beneath the shoulder.' I

6. The combination with a hollow insulating portion having alockingshoulder therewithin, of a hollow connecting member arranged within theinsulating portion and having a, plurality 'of openings, of lockingdevices movable within said openin gs and having engagement with theaforesaid locking shoulder, retaining means engaging the lockingdevicesto prevent their shoulder, and

permit the locking member to bethreaded a plurality a cementitiousfilling medium within the connecting member engaging the retaining meansand preventing withdrawal of the 7. The combination with an insulatingportion having a locking shoulder extending partially thereai'ound, of acap secured upon the insulating portion and carrying a mov-' ablelocking member adapted to be brought into locking relation with'theshoulder by turning the cap on the insulating portion.

I BENTLEY A. rninrrorif I

